Litter box



FIG. 1 is a top left front perspective view of a litter box showing the new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a rear view thereof;

FIG. 7 is a left side view thereof; and,

FIG. 8 is a right side view thereof.

The broken lines shown in the drawings depict portions of the litter box that form no part of the claimed design. 

CLAIM The ornamental design for a litter box, as shown and described. 